This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In a previous genome-wide scan, we identified BANK1 as a gene involved in susceptibility for SLE. Follow-up studies identified two polymorphisms in BANK1 that are specifically associated with SLE risk and which have an impact on the function and expression of BANK1 isoforms. We will work to test the hypothesis that the risk isoforms cause increased autoantibody production through disruption of molecular signaling cascades. B cells will be stratified according to their activation status and BANK1 expression levels will be tested in these subsets to identify any correlations.